[lxc-users] Access /dev/mem in lxc

[Ganesh Sathyanarayanan]

Hi All,

This is similar to a post by a John sometime in Aug-2010. He was trying to
run Xorg in an lxc which required access to /dev/mem. Am trying to run a
custom/proprietary application that needs the same (access to /dev/mem).

I have a privileged container - as in I've created the container as root on
my device and start it as root. (root is the usually only user on embedded
devices, unlike PC)
I have been trying to ‘expose’ the /dev/mem device to my container because
the application I run there needs it.
However, am unable to do so - I always end up with a “Operation not
permitted” error when I try to open /dev/mem. The following are the
different things I tried
1) lxc-cgroup.devices.allow = c 1 1 in the conf file (and doing a "mknod
/dev/mem c 1 1" on the container)
2) lxc-device -n <name> -- add /dev/mem to a running container (this causes
/dev/mem to appear in the container without having to run any extra
commands such as mknod. But opening it still fails)
3) lxc.aa_profile = unconfined (along with steps 1 & 2)

Please advise what I can do to make /dev/mem accessible in lxc. A simple
test am doing prior to running my actual application, is something like
"head /dev/mem" in the container and check that it displays anything (other
than Operation not permitted error).

Thank you very much.

Ganesh S.
ps: Since this is my first mail to this group, please excuse if something
is not right
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